Number Flashcards
What is a factor?
A number that divides exactly into another.
Eg 8 is a factor of 40.
What do the letters L C M stand for?
lowest common multiple
What is the most efficient method to find the HCF and LCMs of 148?
Break the number into its prime factors using a prime factor tree.
What are the first six prime numbers?
2,3,5,7,11,13
How do you convert a fraction to a decimal without a calculator?
Try to find an equivalent fraction where the denominator is a multiple of 10 or 100, because these values are easy to divide by.
How do you convert a decimal to a percentage?
You need to multiply by 100.
How do you convert a percentage to a fraction?
Write the percentage value over 100. If possible, cancel the fraction to its simplest form.
What do the letters H C F stand for?
Highest common factor
When do you need to find a common denominator?
When you add or subtract fractions.
How do find a common denominator?
Look at denominators and if one is a multiple of the other, make the smaller value the same by multiplying. If both values are different, then find the LCMs of them.
If I multiply a positive number by a negative one, what sign is my answer?
Negative.
Two signs are different when you multiply the answer is negative.
If I square a negative number what happens?
The number is multiplied by itself and it becomes positive.
Which is larger one ninth or one seventh?
One seventh because your amount is cut into seven equal pieces, not nine, so it must be larger.
How do find the length of a square if you know it’s area is 36 cm^2
Square root 36
Because to get the area of a square you multiplied the length by itself.
How do you round 28.785 to 1 significant figure?
A number just round it to the nearest 10. So the answer would be 30
How many cm are in 1m^2?
10000
Because there are 100 cm in 1m and when you square you multiply the number by itself.
How do you simplify ratios?
By dividing all the parts in the ratio by a common factor.
How do you divide 672 by 1.6 without a calculator?
Multiply by ten to get 16 and 6720. Now use long or short division to divide 6720 by 16 to get your answer.
How many km are in 5miles?
8
